A canisterized missile is typically launched using the missile's launch booster—so called “hot launch.” When the booster fires, a plume of very high-temperature, high-velocity exhaust gas is generated. The plume, which in some cases contains metallic particulates, is very erosive. Direct exposure to the plume would have an adverse effect on the missile, the missile canister, other launch structures, and the surrounding environs (e.g., deck of a ship, etc.).
As a consequence, most missile-launch systems include an exhaust-gas management system, which directs the booster plume away from the missile and launch structure. To withstand the plume's extreme conditions, the launch structure, as well as the exhaust-gas management system itself, must incorporate thermal-protection and erosion-protection materials.
Incorporation of the exhaust-gas management system and the protective materials necessarily enlarges the missile-launch system as well as increasing its weight, cost and complexity. Furthermore, the heating of the launch structure and deck that results from hot launch creates a residual thermal signature. This signature is readily detectable by various sensors, and therefore potentially compromises the survivability of the missile launcher and, indeed, the ship or vehicle that supports it. Also, by its nature, hot launch technology increases the volatility of a missile due to the presence of the additional energetics, which are stored in the missile's booster.
To address the problems of hot launch, “cold-launch” systems have been developed. A booster is not used to eject the missile from the missile canister during cold launch. Rather, some other means that does not generate the high temperatures or the erosive flow of a missile plume is used. For example, cold launch systems that use air bag inflators and electromagnetics to launch missiles are under development or are currently in use.
The absence of the launch booster eliminates the risk, formerly borne, associated with storing potentially harmful energetics on the launch platform. In addition, since an exhaust-gas management system is not required for cold launch, the launch system is necessarily smaller and requires far less deck space. Furthermore, the deck heating/thermal signature problem is substantially reduced or eliminated since, during cold launch, the missile's primary booster fires only after the missile clears the canister is and well away from the deck.
But existing cold launch systems are not without drawbacks of their own. One drawback is that most cold launch system include a substantial number of additional components, which raises reliability issues. Another drawback is that in some cold launch systems, the missile is exposed to high-pressure gas from a gas generator (that provides the pressure for launch). Also, electromagnetic launch systems require a great deal of electrical current to launch a missile.
What is needed, therefore, is a new type of cold-launch system that avoids the drawbacks of existing cold-launch technologies.